test/java/awt/Modal/ModalInternalFrameTest/ModalInternalFrameTest.java

rev 14031 : 8160974: [TESTBUG] Mark more headful tests with @key headful.

This is a backport of fe58d505fffd from jdk9. 228/596 hunks apply without
modifications. 16 hunks required manual rework. The remainder were for files
not present in jdk8u.

@@ -21,10 +21,11 @@
  * questions.
  */
 
 /*
   @test
+  @key headful
   @bug 6518753
   @summary Tests the functionality of modal Swing internal frames
   @author artem.ananiev: area=awt.modal
   @run main/timeout=30 ModalInternalFrameTest
 */